I got my finger on the mothafuckin' pistolAiming it at a pig, Charlotte's web is going to miss you

This line references E. B. White’s Charlotte’s Web. In the book, a pig named Wilbur is saved from being slaughtered by a spider named Charlotte, who writes phrases in her web to dissuade his farmer.

In Kendrick’s case, a pig is a slang term for a police officer who isn’t saved from the wrath of Kendrick’s weapon. This imagery relates to the Black Panther Party who was very militant towards law enforcement during confrontations.